Synthesis of bimetallic Co–Pt/cellulose nanocomposites for catalytic reduction of p-nitrophenol

The sonochemical synthesis of Co–Pt nanoparticles anchored on cellulose nanofibers (CNFs) was demonstrated. An enhancement in the catalytic activity of the synthesized Co–Pt/CNF nanocomposite catalyst was observed for the reduction of p-NP due to synergy effects.

Novel Tough and Transparent Ultra-Extensible Nanocomposite Elastomers Based on Poly(2-methoxyethylacrylate) and Their Switching between Plasto-Elasticity and Viscoelasticity

Novel stiff, tough, highly transparent and ultra-extensible self-assembled nanocomposite elastomers based on poly(2-methoxyethylacrylate) (polyMEA) were synthesized. The materials are physically crosslinked by small in-situ-formed silica nanospheres, sized 3–5 nm, which proved to be a very efficient macro-crosslinker in the self-assembled network architecture. Very high values of yield stress (2.3 MPa), tensile strength (3.0 MPa), and modulus (typically 10 MPa), were achieved in combination with ultra-extensibility: the stiffest sample was breaking at 1610% of elongation. Related nanocomposites doubly filled with nano-silica and clay nano-platelets were also prepared, which displayed interesting synergy effects of the fillers at some compositions. All the nanocomposites exhibit ‘plasto-elastic’ tensile behaviour in the ‘as prepared’ state: they display considerable energy absorption (and also ‘necking’ like plastics), but at the same time a large but not complete (50%) retraction of deformation. However, after the first large tensile deformation, the materials irreversibly switch to ‘real elastomeric’ tensile behaviour (with some creep). The initial ‘plasto-elastic’ stretching thus causes an internal rearrangement. The studied materials, which additionally are valuable due to their high transparency, could be of application interest as advanced structural materials in soft robotics, in implant technology, or in regenerative medicine. The presented study focuses on structure-property relationships, and on their effects on physical properties, especially on the complex tensile, elastic and viscoelastic behaviour of the polyMEA nanocomposites.

Effect of Geometric Error on Friction Behavior of Cylinder Seals

The tribological characteristics of the cylinder directly affect the operation accuracy of the pneumatic servo system. However, the geometric error has a significant effect on its tribological behavior and the related research is insufficient. Thus, the dynamic friction process of rubber seals has been investigated considering the influence of geometric errors. Firstly, based on the self-made friction test platform, the friction force of the rubber seals was studied and the influence law of geometric error on the contact area of the rubber seal ring was revealed. Secondly, the numerical model of the friction and contact of the rubber seals for the cylinder segment was developed by using the finite element simulation method and the influence laws of machining errors, such as roundness and straightness on the friction characteristics, were revealed. Finally, synergy effects of roundness and straightness in the friction behavior of rubber seals considering geometric errors was investigated, which lays a foundation for the accurate prediction of cylinder dynamic mechanical properties.

Eastern enlargement: analysis of development processes in the EU15 in the context of creative destruction

Motivation: Studies on the impact of the Eastern enlargement on economies of the EU15 indicate that the new member states could not be a significant engine for development processes. However, this does not exclude that the Eastern enlargement and acceding countries could have a significant impact on the mechanisms of the development of the EU15. If we consider Eastern enlargement as a Schumpeterian innovation, its long-term effects should be evident in the way creative destruction affects economic development. Aim: The aim of the study was to determine the impact of the Eastern enlargement on the economic development of the EU15 in the context of creative destruction. In particular, the aim of the empirical analyzes was to determine whether and to what extent the enlargement of the EU was a factor modifying the impact of creative destruction on the development of “old” members countries, and to identify the role of the new member states in these processes. Results: Econometric analysis confirmed that creative destruction influenced economic development in the EU15, and that Eastern enlargement was a factor modifying the relationship between creation, destruction, and the rate of change of GDP per capita. The Eastern enlargement has mobilized two opposing forces. The “internal” force resulting from market selection in the EU15, which after 2004 became an active component of creative destruction, contributing however to a lower rate of change in GDP per capita. The “external” force, related to the mechanism of transmission of impulses within the grouping: synergy effects from destruction in new member countries were a catalyst for the development processes of the EU15, and synergy effects from creation were inhibitors for these processes. In the context of our research the “development leaders” can be considered the largest beneficiaries of Eastern enlargement in the EU15.

Historical Forms of Tourism Gradual Transnationalization and the Perpetuum Mobile Behind it

Over the past 70 years, tourism has always been at the forefront of business transnationalization, as it has consistently used all the advantages of the transnational production and distribution system, thereby creating additional competitive advantages on a truly global scale. The purpose of this study is to analyze the evolution of the international travel market, as well as to identify a number of historical stages of its development, which the market has passed on the way to establishing strong international relations and interaction. In this article, transnationalization is defined as a modern form of organizing tourism and hotel business. It was proposed directly by entrepreneurs as one of the possible solutions to classic market problems (including limited demand and factors of production). These market problems intensified in the second half of the last century, and all of them directly influenced the development of tourism. The study analyzed the driving forces of transnationalization of the tourism and hospitality sectors, taking into account the economic effect of the synergy of transnationalization. Expansion of tourist activities of the sectoral transnational corporations along with their gradual transformation into influential subject of the world economy. All of the considered in the article synergy effects from tourist business transnationalization have nearly simultaneous impact on the process of tourist services’ production.